Metal nanoparticles have received much attention in various fields due to characteristic properties such as a significantly wide surface area as compared to volume, a quantum confinement effect, a surface plasmon effect, and the like.
These properties of the metal nanoparticles are significantly affected by a size and surface thereof and a supporter, and as the supporter on which the metal nanoparticles are loaded, a polymer or dendrimer, silica, metal oxides, and the like, have been mainly used.
Particularly, a structure in which the metal nanoparticles are loaded on the supporter has been actively studied in a catalyst field, but there are problems such as a low surface activity, low stability, low dispersibility, continuous inactivation/leaching of a catalyst, or the like. As an example, a metal catalyst loaded on mesoporous silica is known to be significantly unstable and be rapidly inactivated/leached at the time of a catalytic reaction (R. B. Bedford, U. G. Singh, R. I. Walton, R. T. Williams, S. A. Davis, Chem. Mater. 2005).
Further, research into metal nanoparticles which are stable while having a catalytic activity in an eco-friendly solvent such as water has been importantly considered in a green chemistry field due to environmental and economical reasons and safety. However, research into catalytic reactions in water using a structure in which nanoparticles are loaded on a supporter has not yet been actively conducted (M. L. Kantam, S. Roy, M. Roy, B. Sreedhar, B. M. Choudary, Adv. Synth. Catal. 2005).